1. Priority Claim
Priority is claimed for this invention and application, a corresponding application having been filed in Germany on Mar. 25, 2002, No. 102 13 200.3.
2. Field of the Invention
The invention relates to a resectoscope.
3. Description of the Related Art
With known resectoscopes, after a certain number of individual cuts with which tissue parts have been detached, it is usual to lead away the detached parts together through the outer shank of the resectoscope. For this it is first necessary to remove the so-called working insert from the outer shank of the resectoscope in order to be able to make available a sufficiently large cross section for leading away or suctioning away the tissue parts. This manner of proceeding is relatively time-consuming and is thus a burden to the patient.
From WO 98/43531 there is known a resectoscope whose cross section is divided into two parts by a separating wall, a larger part, which forms the suction channel, and a smaller part in which the optics shank is arranged and which serves as a supply channel. In the inside of the suction channel there is arranged the guide and actuation rod for a cutter loop. This leads to a narrowing of the suction channel; furthermore there exists the danger that tissue parts to be suctioned catch on the actuation elements for the cutter loop.
It is the object of the invention to create a resectoscope which permits an improved and quicker leading away of the detached tissue parts.
The resectoscope according to the invention comprises an outer shank in whose inside there is formed a supply channel and suction channel which extend parallel to the outer shank. A rinsing fluid is led through the supply channel into the body cavity to be operated on in order to produce an excess pressure in this. The rinsing fluid may be continuously supplied through the supply channel and led away through the suction channel so that one maintains a constant flow of fluid. At the same time the same quantity of fluid is led away through the suction channel as is supplied through the supply channel in order to maintain the excess pressure in the body cavity. According to the invention the suction channel has a larger cross section than the supply channel. This design permits detached tissue parts, so-called chips to be led away through the suction channel without previously having to remove the working insert from the outer shank. The arrangement thus permits chips to be continuously led away during an operation without the operation having to be interrupted for removal of the working insert from the resectoscope. In this manner an operation may be carried out in a manner which is less time-consuming and which is less of a burden to the patient. Since a continuous change of instruments is avoided, the required fluid balancing for avoiding the feared fluid-overload may be carried out more simply, securely and accurately. The suction channel in a first half of the cross section of the outer shank extends parallel to this. At the same time the suction channel preferably has a cross-sectional shape which corresponds essentially to half the cross section of the outer shank. In this manner one may create a very large suction channel which permits the suctioning away of larger chips. In a second half of the cross section of the outer shank, in its inside there extends an optics channel as well as at least one electrode guide tube outside the suction channel and parallel to the outer shank. This arrangement permits half of the inner cross section of the outer shank to be used for the suction channel, whilst the other half is used for the remaining channels, i.e. the optics channel as well as the at least one electrode guide tube. In this manner in the inside of the outer shank there is made available a very large suction channel.
Preferably at the distal end of the resectoscope, i.e. at the end proximal to the patient there is provided a cutter loop which delimits a cross sectional area which in its dimension is smaller or equal to the cross sectional area of the suction channel. The cutter loop serves for detaching tissue parts, as with known resectoscopes. For this the cutter loop is preferably designed as a U-shaped bow which is led through the tissue. The cross sectional area delimited by the cutter loop is determined by the loop size. The size of a detached tissue part or chip is defined by selection of the loop size. Since the loop size is selected such that the cross sectional area delimited by the cutter loop is smaller or equal to the cross sectional area of the suction channel, one may ensure that the detached chips have a size which is smaller than the cross section of the suction channel so that the chips may be safely led away through the suction channel. One may thus prevent the detached chips from sticking in the suction channel and blocking this.
The outer shank preferably has a circular cross section and the suction channel a semicircular cross section. In this manner the suction channel may fill half the inner space or the inner cross section of the outer shank and use it for transport of the chips. However other cross sectional shapes are also conceivable. Thus the outer shank for example may be formed ovally, wherein the suction channel has a cross sectional shape which corresponds essentially to half the inner cross section of the outer shank. The outer contour of the suction channel may be formed corresponding to the shape of the inner cross section of the outer shank, so that the space available in the inside of the outer shank may be optimally exploited.
The supply channel is preferably formed by the cross sectional space surrounding the suction channel, the optics channel as well as the electrode supply tube. This means the supply channel is not formed as a separate shank or as a separate tube as the discharge channel but is formed by the remaining free space in the inside of the outer shank. In this manner the cross section of the outer shank may be optimally exploited and no unused free spaces remain in the inside of the outer shank. Thus a sufficiently large cross section for the supply channel may be made available also with a large cross section of the outer shank according to the invention. The supply channel may have a cleaved cross sectional shape since only a fluid without large particles is to flow through it. The discharge channel on the other hand must have a large, non-fissured, coherent cross sectional area in order to allow the passage of chips.
Preferably there are provided two electrode guide tubes which are arranged on two diametrically opposed sides of the optics channel. The electrode guide tubes preferably have a smaller cross section or diameter than the optics channel. In this manner with a round or oval cross section of the outer shank one may optimally use the free space remaining for the optics channel as well as the electrode guide tubes, i.e. half the cross sectional area of the outer shank. If the suction channel fills half the inner cross section of the outer shank then with a round or oval cross section there remains a semicircular cross section or a cross section in the shape of a half oval. The optics shank with a larger diameter is preferably arranged centrally in order to optimally exploit the section of the greatest height of the cross sectional area. There is sufficient space for the electrode guide tubes in the remaining lateral regions with a smaller cross section. With this arrangement the two electrode guide tubes are furthermore arranged distanced as far as possible to one another. This permits a secure and in particular rotationally secure guiding of the cutter loop and thus a more precise separation of tissue parts. Alternatively the electrode may also be axially guided by way of an individual guide tube encompassing the optics.
With the first embodiment form the limbs of the cutter loop usefully extend parallel to the outer shank through the electrode guide tube. The cutter loop is formed bow-shaped or U-shaped. The two limbs are essentially bent at right angles so that the bow of the cutter loop extends bent at an angle in a plane and in particular transversely or normal to the further direction of extension of the limbs. Since the two limbs run parallel to the outer shank through the electrode guide tubes, the bow of the cutter loop thus extends bent at an angle in one plane and preferably essentially normally to the longitudinal axis of the outer shank. By way of linear movement of the limbs in the inside of the electrode guide tubes in their longitudinal direction the cutter loop is moved distally and proximally in order to detach tissue parts.
According to a preferred embodiment form the suction channel is further connected to a vacuum source via a first valve. In this manner by opening this valve one may produce a vacuum in the inside of the suction channel in order to suction off detached tissue parts or chips through the suction channel. The valve may be opened for a short time during operation so that detached chips may be suctioned away without having to interrupt the operation procedure.
Preferably the first valve is coupled to an actuation means for a cutter loop in a manner such that the valve is opened in a predefined position of the cutter loop. This position is preferably the proximal end position of the cutter loop in which the cutter loop is located after the procedure of separation of the tissue. By way of such a coupling of the valve to the actuation means for the cutter loop it is achieved that after completion of the separation procedure, the detached tissue part is directly suctioned away in that the valve is opened and a vacuum impulse is produced in the suction channel. The suctioning away of the detached tissue parts may thus be effected automatically at the correct point in time. Alternatively the valve may however also be actuated by the operator independently of the cutting procedure for example via a button or foot switch.
It is further preferred for the first valve to be activated via a time impulse means which opens the valve for a predefined time duration given an actuation signal, in order to produce a suction impulse in the suction channel. A suction impulse may be produced for a predefined time duration by way of this arrangement. This is important when suctioning in order to ensure that the excess pressure in the body cavity is not reduced to an extent such that this disintegrates or collapses. In this manner one may prevent too long an opening of the valve and a thus associated suctioning of too large a quantity of fluid. The suction impulses may be selected very short since it is not necessary to suction a detached chip directly through the complete suction channel out of the resectoscope. On the contrary it is indeed sufficient for the chip firstly only to be suctioned into the suction channel and for it to remain there. After separating the next chip when a new suction impulse is produced, the previously detached chip then travels further in the suction channel in the proximal direction when the subsequently detached chip is suctioned into the suction channel. This means that the detached chips travel in steps through the suction channel successively distanced to one another like the carriages of a train.
Usefully the first valve is arranged directly on or directly in a connection piece of the suction channel, i.e. essentially directly at the proximal end of the suction channel. This arrangement has the advantage that one does not need to arrange flexible tubings between the first valve and the connection piece at the proximal end of the suction channel. The arrangement of flexible tubings between the first valve and the suction channel with an impulsed suctioning has the disadvantage that on opening the first valve a vacuum prevailing at this leads to an elastic deformation, i.e. to a narrowing of the cross section of the flexible tubing between the valve and the suction channel. By way of this, on the one hand the suction power prevailing at the suction channel is reduced. On the other hand the flexible tubing with the subsequent closure of the valve on account of the sluggishness of the flow may elastically widen and thereafter may again relax in a spring-elastic manner, by which means the flow direction on account of the closed valve is deflected in the direction of the resectoscope, by which means cut-away tissue parts, in particular the last tissue part cut away, is rinsed out of the distally open suction channel back into the body cavity. This disadvantage is avoided by the arrangement of the first valve directly on the proximal end at the suction channel.
It is further preferred for a return valve to be provided on or in the proximal end of the suction channel which permits a flow only in the proximal direction. This return valve prevents a reversal of the flow direction by way of which detached tissue parts could be rinsed through the distal end of the suction channel back into the body cavity.
Preferably the valve is designed as a magnet valve which is activated by an electrical actuation signal. The electrical activation of the valve permits a very variable and simple adjustment of the opening duration of the valve. The magnet valve is preferably designed as a flexible tubing squeezer which clamps a suction flexible tubing. The clamping is released on opening the magnet valve so that fluid may flow through the suction flexible tubing in the direction of the vacuum source in order to be able to suction fluid and detached chips out of the body cavity.
According to a further preferred embodiment form the suction channel is connected to a discharge conduit for a continuous discharge of fluid via a second valve. If this second valve is opened a small quantity of rinsing fluid may be led away continuously through the discharge conduit, for example into a second collection container.
Preferably the second valve is coupled to the first valve in a manner such that the second valve is closed when the first valve is opened. This allows a small quantity of rinsing fluid to be continuously led out of a body cavity via the opened second valve and the discharge conduit even when the first valve is closed. The coupling of the first and the second valve may be effected in a purely control-technological manner if both valves are designed as magnet valves. In this case a control apparatus may activate the two valves such that either the second valve is opened in order to provide a continuous fluid discharge or the first valve is opened in order to lead away detached tissue parts out of the body cavity. By way of this measure it is achieved that detached chips may only get into the collection vessel envisaged for accommodating the tissue parts. Instead of coupling the two valves to one another by way of a suitable electrical activation in the described manner, a purely mechanical coupling is possible; thus both valves may be grouped together in a two-way valve which reciprocally releases a vacuum conduit or the discharge conduit. Such a two-way valve is preferably likewise designed as an electrically activated magnet valve.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.